Added tests for implementation error we came up with in the need for speed sprint.
diff --git a/Lib/test/string_tests.py b/Lib/test/string_tests.py
index 3a5fbfe..f76a9eb 100644
--- a/Lib/test/string_tests.py
+++ b/Lib/test/string_tests.py
@@ -882,6 +882,25 @@
else:
self.checkcall(format, "__mod__", value)
+ def test_inplace_rewrites(self):
+ # Check that strings don't copy and modify cached single-character strings
+ self.checkequal('a', 'A', 'lower')
+ self.checkequal(True, 'A', 'isupper')
+ self.checkequal('A', 'a', 'upper')
+ self.checkequal(True, 'a', 'islower')
+
+ self.checkequal('a', 'A', 'replace', 'A', 'a')
+ self.checkequal(True, 'A', 'isupper')
+
+ self.checkequal('A', 'a', 'capitalize')
+ self.checkequal(True, 'a', 'islower')
+
+ self.checkequal('A', 'a', 'swapcase')
+ self.checkequal(True, 'a', 'islower')
+
+ self.checkequal('A', 'a', 'title')
+ self.checkequal(True, 'a', 'islower')
+
class MixinStrStringUserStringTest:
# Additional tests for 8bit strings, i.e. str, UserString and